#include <stdio.h>

// 需要使用地址传递
void my_swap(int *p, int *q){
	int temp = *p;
	*p = *q;
	*q = temp;
	return;
}

int main(int argc, const char *argv[])
{
	int a = 10;
	int b = 20;
	my_swap(&a, &b);
	printf("a = %d  b = %d\n", a, b); // 20 10

	return 0;
}
